As of 2010, CBP operated four Predator UAVs out of Arizona, one of out Texas and one out of North Dakota.

The unit cost for one Predator is about $4.5 million, according to DHS estimates. But the costs of operating a UAV can become more than double the costs of operating a manned aircraft, said the Congressional Research Service (CRS) last summer. (See Homeland Security: Unmanned Aerial Vehicles and Border Surveillance.)

Operating one UAV could take a crew of up to 20 Border Patrol agents, according to the CRS analysis. CBP’s Air and Marine Branch last fall pegged the per-hour cost of operating a Predator UAV for border surveillance at $3,234.

Based on that figure, keeping one UAV in the air every hour of the year would cost about $28.5 million.